Unlike most incremental upgrades between models, I'd say the shift from the Core Duo to the Core 2 Duo -- in tandem with some strategic moves by Apple to make the new laptops even more of a value -- is a bigger deal than usual. In the not-so-distant past, a laptop "update" usually meant a slightly faster processor, a slightly larger hard drive, maybe some more video RAM and -- well, that was sometimes about all there was.

This time, would-be buyers get a better and faster processor with a number of under-the-hood changes that keep heat and power use under control; a substantial upgrade in hard drive options that includes a 200GB drive for mobile users who really need storage space as well as a 160GB drive that uses new perpendicular technology; and an across-the-board doubling of RAM to either 1GB or 2GB depending on which MacBook Pro you're talking about. Prices remain the same.

The stock 15-in. MacBook Pro starts at US$1,999, but the model tricked out by Apple for this review is the $2,499 version. In addition to an upgrade from the dual-core 2.16GHz Core 2 Duo to the 2.33GHz chip, the model in front of me has 2GB of RAM; the 160GB, 5,400-rpm hard drive; an ATI X1600 graphics card with 256MB of video RAM (the stock card offers 128MB of VRAM); and a dual-layer SuperDrive and a FireWire 800 -- both of which were offered on the 17-in. model before and are new to the smaller MacBook Pro). There's also the usual wireless networking capabilities, a built-in iSight Web cam that has a newly hidden indicator light, the now-standard backlit keyboard and other carryovers from previous models.

In terms of speed, I used the benchmarking application Xbench, which measures a number of parameters -- CPU, RAM, graphics and hard disk -- to arrive at an overall score. For comparison purposes, Xbench reported a score of 90 for the first-generation Core Duo version of Apple's 17-in. MacBook Pro. Note: That model had the slower 2.16GHz chip, but a faster 7,200-rpm 100GB hard drive.

So how does this one compare? Running on the new MacBook yielded a score of 108 -- a 20 percent gain for a chip that, as Apple Product Manager for Portables Todd Benjamin notes is "less than 10 percent faster" than the Core Duo processor. Part of the 20 percent jump -- Apple found even faster gains in its own tests of professional apps such as Final cut Pro -- comes from changes in the architecture of the chip itself.